Question

The element rhenium (Re) exists as two stable isotopes and 18 unstable isotopes. Rhenium-185 has in its nucleus

Answer 1

Answer:

d. 75 protons, 110 neutrons

Explanation:

In an isotope, the number next to the number of the atom is the mass number (Protons + neutrons). Rhenium has as atomic number 75, that means Rhenium has 75 protons. As atomic mass, 185, is the sum of protons and neutrons, number of neutrons is:

185 - 75 = 110 neutrons

Thus, right answer is:

d. 75 protons, 110 neutrons